Refrigerating system



F. W. SCHWINN REFRIGERATING SYSTEM Filed Nov. 16, 1925 2 Sheets-Sheet 1f 192222 a 6 577)? v F. W. SCHWINN REFRIGERATING- SYSTEM Filed Nov. 16,1925 2 Sheets-Sheet 2 Patented July 10, 1928.

. UNITED STATES Application filed November 16, 1925. Serial No. 89,844.

This invention relates to improvements in refrigerating systems and moreespecially to a system of that kind having two or more coolingcompartments.

Among the features of my invention, is the provlsion of means whereby aplurality of cooling compartments ma be taken care of by one compressor;even ough difierent temperatures may be required in the separatecompartments.

My invention will be found especially useful in all cases where there isa plurality of cooling compartments operating under differentconditions. In such cases, by the use of my invention, the differentcompartments may be handled by one compressor. For example, at sodafountains where ice cream and syrups are kept in cooling compartments,it frequently happens that it is des'irable to keep the differentcompartments at diflerent temperatures. This may be easily done by theuse of my. invention.

Other features and advantages of my invention will appear more fully asI proceed with my s ecification.

In that orm of device embodying the features of my invention, shown inthe accompanying drawings, Figure 1 is a view in side elevation, partlydiagrammatic, showing the complete apparatus; and Fig. 2 is a verticalsectional view showing one of the expansion valves and thermostaticswitch.

In general, it may be stated in apparatus of this kind, therefrigerating liquid passes from the pump or compressor to an expansionvalve, thence to the cooling coil in the cooling compartment and backagain to the compressor.

In the practice of my invention, a separate expansion valve is providedfor each coolin compartment, and such expansion valve In turn iscontrolled by a thermostatic switch operated by changes in temperaturein the particular compartment. When the temperature in a certaincompartment rises to a given point, the thermostatic means operates toopen the expansion valve and permit the flow of the refrigerant. Uponthe temperature dropping to a desired point, such flow is automaticallyshut off in order to prevent the compartment from becoming too cool.Each compartment, having its own expansion valve andthermostatic switch,operates independently of the others; and each switch may be set asdesired in order to the. compartment controlled thereby.

Each of thethermostatic devices also controls an electric switch so thatwhen all of the expanslon valves for all of the compartments are closed,the electric motor operatmg the compressor will be shut off. As long asany one compartment requires refrigerant, however, the operation of thecompressor Wlll continue.

As shown in the drawings 10 indicates a pump or compressor operated byan electric motor 11. 12 indicates a suitable source of current supply.The particular construction and operatlon of the pump or compressor, andthe electric motor, form no part of the present invention and,consequently, the same are not shown in detail. l

13 and 13 indicate separate cooling compartments here shown as two innumber. It is to be understood that there may be as many of thesecooling compartments as de- PATENT. orries.

give the required temperature in sired. Each of the cooling com artmentsis supplied with a cooling poil in 14 and 14" respectively.

15 represents the feed pipe carrying the 'cated by refrigerant fluidfrom the compressor to the cooling coils and 16 indicates the return ipefrom the coils to the compressor. ese parts are also of well-knownconstruction and are not shown in detail.

In connection with each of the cooling .coils there is also provided athermostatically operated expansion valve and electric switch. In Fig.1, these devices are indicated in general by 17 and 17 respectively. Oneof these devices is shown more in detail in Fig. 2. v As shown in Fig.2,.the expansion valve comprises a casting 18 havin an inlet open-' ing19 at the bottom to whic the pipe 15 is joined. 20- indicates aremovable seat threaded into the upper end of the inlet .opening 19..Lyin on the valve seat 20 is a valve head, 21 adagted to close theorifice 22 therein.

Arranged above. the valve head 21 is a diaphragm 23 and lying above thisis an arm 24 pivoted at 25 at one side of the diaphragm and extendingdiametrically across the same. The center part of the arm 24 is bentdownwardly as indicated by 24 to lie close to the diaphragm 23. The freeend of the arm 24 as mdicated by 24" is provided with an adjusting screw26, the lower no I I ends end of which rests on the upper end 27 of arod carried by a sylphon or temperature re- .sponsive element 280i anydesired construc carrying at its lower end a glass tube 33 havin thereinat one end the two electrical termlnals 34, 34. Within the tube 33is adrop of mercury cent 37 is adapted to yleldingly holdthe lower,

Theuppenend of the arm 31 near the pivot 32 carr1es a short nose 36lying adjathe shoulder 30 on the nut 29. A spring end of the arm'to theleft. (as viewed in Fig. 2). The two' electrical terminals 34, 34 areconnected to the two wires 38 and 39 which form a part of the circuit 12controllin the motor 11. 4

e construction and operation of the mechanism 17" is the same as that ofthe one just described. 39" and 38 indicate the two wires leadingfrom'the electrical switch on this device. 15 indicates the pipecarrying the refrigerant from the compressor and 16 indicates the returnpipe from the coil. It will be noticed that both electrical switches areconnected with the circuit 12 controlling the electric motor 11 so thatif either of the electrical switches be closed, the motor will operate;but that if both be opened, the motor will stop. I

40 indicates a tube connected with the sylphon'28 and providedwith abulb 41 lying 1n the cooling compartment 14.

In the o eration of the device, the nut 29 is adjuste on the threadedpart 28 of the rod 27 so that theshoulder 30 will engage the nose 36 onthe arm 31 and rock the same to cause the mercur 35 to flow toward thecontacts 34, 34 and c ose the switch when the temperature in thecompartment 14 rises to a certain point. The action is caused by theexpansion of the fluid used in the sylphon which fluid also fills thepipe 40 and the bulb 41 lying in the cooling compartment. When thetemperature rises to a given point this fluid expands causing thesylphon 28 to expand thus raising the shoulder 30;

The adjusting screw 26 on the arm 24 is also so adjustedthat atsubstantially the same time, the upwardmovement of the part 27 carriedby the sylphon will raise the central portion 24 of the arm 24 restingon the diaphragm 23 and permit the. valve head 21 to rise and theexpansion valve to open.

The arm 24 is yieldingly pressed downwardly by a spiral spring .45 asshown. I

It will be seen that each'of the coolin' compartments is' substantiallycontrollei When the temperature in either one reaches a predeterminedpoint the corresponding ture drops to a certain point.

.mounted member 50 which has my hand this 14 day of will thereupon bestarted (unless it is al- .ready runnmg')" and the flow of refrigerantthrough the cooling coil in that compartment will be permltted untilthetemperatemperature falling to a predetermined point, the'sylphon willcontract, to close the Upon the expansion valve and open the electricswitch.

It will be noted, however, that both electric switches must be open inorder to stop operation of the compressor.

The .sprin 45 which presses down the arm 24 is he d at its upper end bya rigidly t readed in it a screw 51, the lower end of which, asindicated by 51 extends through a hole in the arm and acts asa stop forthe diaphragm 23. The screw 51 can be adjusted upwardly or downwardly inthe member 50 in order to vary the position of such stop, andconsequently vary the maximum openin of the ex ansion valve. 52indicates a loc nut to ho d the screw 51 in its adjusted position. 53indicates diagrammatically a condenser between the compressor and theexpansion valves.

While I have shown and described certain embodiments of my invention itis to be understood that it is capable of many modifications. Ghanges,therefore, in the construction and arrangement may be made withoutdeparting from the spirit and scope of the invention as disclosed in theappended claim, in which it is my intention to claim all noveltyinherent in my invention as broadly as ssible in view of the prior art.

What I c aim as new, and desire to secure by Letters Patent, is: p 1 Ina refrigeratmg system; a plurality of cooling compartments; acompressor; a con denser; a cooling coil in each compartment;connections between each cooling coil and the condenser; an expansionvalve in connection with each cooling coil adapted to control the flowof refri rant from the condenser to the cooling coll; thermostaticallycontrolled means in connection with each'expansion valve adapted toregulate the opening of said expansion valve in accordance with changesin temperature in the corresponding cooling compartment; an electricalswitch operated by each of said thermostatically controlled meansadapted to be opened upon the expansion valve being closed and viceversa; a motor for driving the compres- In testimony whereof, I havehereunto set Nov. .1925.

FRANK w. sonwnm.

sor; and electrical connections between said 3 switch and the motorwhereby said-compressorwill be stopped when allof said switches areopen.

